PURPOSE: To obtain a hollow molding material excellent in mechanical strength, rigidity, impact resistance, heat resistance, dimensional stability, and surface smoothness from a more easily available polyamide resin for injection molding.

CONSTITUTION: This hallow molding material comprises 50-96 pts.wt. polyamide resin (composition) having a relative viscosity of 1.8-4.0, 0.5-10 pts.wt. glutarimide copolymer comprising 30-89mol% glutarimide units, 10-69mol% units derived from an α,β-unsaturated ethylenic monomer, and 1-10mol% acid (anhydride) units, and 3-5 pts.wt. whiskers having an average fiber diameter of 0.05-4μm, an average fiber length of 5-500μm, and an aspect ratio of 10 or higher.